Apparatus for drilling holes.



S. T. SKEEN.

APPARATUS FOR DRILLING HOLES.

APPLICATION FILED HEPT. 25, 1911.

3 SHEETS-SHEET 1.

7206]? 23 0/. \jawae 22 $6613.

COLUMN-A INaTON. n.

Patented Nov. 18, 1913.

S. T. SKEEN.

APPARATUS FOR DRILLING HOLES.

APPLIOATION FILED SEPT. 25, 1911.

3 SHEETS-$112121 2.

Patented Nov. 18, 1913.

masmgn. APPARATUS FOR. DRILLING HOLES.

APPLICATION FILED SEPT. 25, 1911. 1,078,701. Patented Nov. 18,1913.

3 SHEETS-SHEET 3.

COLUMBIA PLANOORAPH cu" WASHINGTON, lav c UNITED STATES PATENT OFFICE.

SAMUEL T. SKEEN, 0F SANDOVAL, ILLINOIS, ASSIGNOR 0F ONE-SIXTH TO CARY S. HEATON, ONE-SIXTH TO HENRY C. WORCESTER, AND ONE-SIXTH TO GEORGE M.

WYATT, ALL OF ROODI-IOUSE, ILLINOIS.

APPARATUS FOR DRILLING HOLES.

Application filed September 25, 1911.

To all whom it may concern Be it known that I, SAMUEL T. SKEEN, a citizen of the United States of America, residing at Sandoval, in the county of Marion and State of Illinois, have invented certain new and useful Improvements in Apparatus for Drilling Holes, of which the following is a specification.

This invention relates to expanding drills, and has for its primary object to provide an improved construction, combination and arrangement of parts in an apparatus of this character whereby drilling operations can be accomplished more simply, economically and effectively.

One of the objects of the present invention is to provide an improved expansible bit with means for expanding said bit automatically by the power which drives it to its work; and further means for contracting said bit by the power which retracts it.

Toward the attainment of this object my invent-ion contemplates the provision of an improved drill head and blade holder to which cutting blades or bits are movably connected, and improved means for detachably connecting said drill head and blade holder to the shank of an ordinary auger used in coal mining and similar operations, said connecting means being adapted to permit a relative movement between said shank and drill head for expanding and contracting the expansive bit comprised of said blades.

Other and further objects will appear in the specification and be specifically pointed out in the appended claims, reference being had to the accompanying drawings exemplifying the invention in its application to a coal miners drill.

In said drawings: Figure 1 is a side elevation of a portion of a miners drill, provided with my improvement the expansive bit being shown in contracted or non-drilling position. Fig. 2 is a side elevation similar to Fig. 1, showin the bit expanded. Fig. 3 is a section of t e same, parts being broken away and parts being shown in elevation. Fig. 4 is an end view of Fig. 1. Fig. 5 is an end view of Fig. 2. Fig. 6 is an elevation corresponding to Fig. 2, but taken at ri ht angles thereto. Fig. 7 is a section on the line VII-VII, Fig. 2. Fig.

Specification of Letters Patent.

Patented Nov. 18, 1913.

Serial No. 651,094.

8 is a detail perspective view of the blade operating member which is constituted by a detachable portion of the drill shank constructed in a peculiar manner according to the principles of my invention. Fig. 9 is an end View of the drill head and blade holder detached. Fig. 10 is a view similar to Fig. 3, with the detachable connecting member shown in elevation. Fig. 11 is a view similar to Fig. 10 with the blades inoperative. Figs. 12, 13 and 14 are diagrammatic side elevations showing the application of my invention to an improved method of drilling holes by a successive employment of blades of different sizes. Fig. 15 is a diagrammatic sectional view illustrating the hole constructed in sections by gradually increasing diameters by the successive employ ment of the device shown in Figs. 12, 13 and 14. Fig. 16 is a similar diagrammatic View illustrating a hole resulting from the employment of drills of present well-known construction.

Referring first to Fig. 16, the usual method employed by coal miners contemplates the drilling of a hole in sections 1, 2, and 3 decreasing in diameter from the outer face of the wall inwardly. For this purpose, each miner is commonly provided with a set of three drills which are usually two, four, and six feet long, respectively, and of diameters corresponding to the sizes of the sections 1, 2 and 3. Numerous disadvantages are to be noted in connection with integral drill bars, such as the necessity of frequently forg ing and reforming the drill head with its attendant drawback of frequent removal of portions of the bar which have become unserviceable by reason of too frequent exposure to fire. It is very diflicult to pull such a drill out of a deep hole. And, if by reason of the varying degrees of hardness in the material which is being mined the hole becomes crooked, 'it becomes necessary even to have the drill bar shot out by an explosion. An inspection of Fig. 16 will show that the smallest portion of the hole is that farthest back, into which the powder charge is laid, so that it becomes more difiicult to properly seal the opening. When the explosion occurs, it frequently happens that the inner end of the hole remains substantially intact, and a large quantity of finely divided coal is displaced. It sometimes happens also that the inwardly contracted hole causes the tamping or wadding to wedge, making it impossible to get it back far enough, with the result that it becomes impossible to fire the charge and a considerable loss of powder results. To overcome these objectionable features forms the main general purpose of this invention.

Referring first to Figs. 1 to 5, inclusive, the herein described embodiment of my invention comprises a spiral shank 4, adrill head and blade holder 5 for movably mounting a pair of blades 6, and an intermediate coupling member 7 which is preferably made as a detachable portion of the spiral shank 4, being made to conform thereto. In

v order to adapt the blades 6 to constitute an expansive bit, they are pivotally mounted upon a split cotter 8 which passes through the cheeks 9 provided on the forward end of the holder 5. Each of the blades 6 is formed of a piece of flat tool steel having its outer forward corner deflected at an angle to provide a combined front and side rake to the tool, which, when the blade is in cutting position, brings the forward cutting edge at an angle to the turning axis of the tool. Said cutting blades are provided with bevels 10 forming their front cutting edges, and are made heavier along their outside edges to impart the desired degree of strength at the outer cutting corners of the tool. By means of this construction, the blades are adapted to be folded together as shown in Figs. 1, 4 and 11; while at the same time they may be resharpened time and time again until they are practically entirely worn away, the combined forward and side rake being maintained throughout the period of their service. The detail construction of the drill head and blade holder is best understood from an inspection of Figs. 1, 2, 3, 7 and 9, said holder consisting of a threaded socket 11. The forward end of the blade holder is provided with a pair of offset blade receiving slots 12 which run together in a central opening 13, into which the angular corners 14 of the blades project. Said angular corners 14 are provided by the blades 6 having their rear edges formed atan angle, so that when the blades are in expanded position (as shown in Fig. 10) said angular edges are brought into alinement to rest upon the bottoms of the grooves 12. The rear edges of said blades are formed with bevels 15 to adapt them to cut away any accumulations in the slots 12 during the introduction of the drill into the cavity. Projecting from the forward end of the couling member 7, is a threaded stud 16 which is adapted to screw into and out of the socket 11 of the blade holder. In operation, the blade holder 5 is adapted to be rotated 90 forward and backward. The forward movement is limited by means of shoulders 17 provided on the rear end of the blade holder which engage with similar shoulders 18 on the forward end of the coupling member 7. The rearward movement is limited by the engagement of the blades 6 with the threaded stud 16 in the manner to be presently pointed out. In order to adapt the coupling member 7 to move the blades into their outer positions by a quarter rotation of said coupling member, the forward end of the stud 16 is provided with recesses for receiving the corners 14 of the blades when they are in folded position (see Figs. 7 and 11). For rigidly supporting the blades in expanded position, the end of the stud 16 is slotted to register with the opening 13, and in consequence, with the slots 12 when the coupling member 7 is in its forward position. shown in Figs. 2, 3, and 10. hen the blades are in the positions shown in Figs. 2 and 10, the inner rear edges of the blades are seated upon facets 19 which are merged into the bottom of the recesses hereinbefore referred to by means of cam surfaces 20, said cam surfaces being adapted to force the corners 14 outwardly to bring the blades into expanded position. Cooperating with these facets and cam surfaces for returning the blades 6 to inoperative positions, a pair of oppositely disposed cam surfaces 21, in the form of fragmentary portions of helixes along the axis of the stud 16 are terminated by a pair of lugs 22 against which the rear edges of the blades respectively abut when said blades are in folded position, the fact that the blades are then positively locked against both the stud 16 and the blade holder serving to determine the limit of the rearward quarter turn movement. In order to make the coupling member 7 detachable from the body 4 of the shank, said coupling member is preferably provided with a pair of apertured lugs 23 on either side of the recesses 24 into which a tongue 25 on the shank 4 projects. A pin or rivet 26, extending through alined apertures in the lugs 23 and tongue 25, serves to make the connection.

Referring now to Figs. 12 to 15, inclusive, my improved method for drilling holes for mining purposes will be readily understood. Thus from the outer wall of the coal or other material, a hole 27 is drilled by means of the expansible blades shown in Fig. 12, which may be such as have been reduced in size by long service and resharpening. At the inner end of the hole 27, is next drilled a hole 28 of larger diameter for which purpose the apparatus shown in Fig. 13 can be 125 conveniently employed, embodying blades which have been somewhat reduced in size by use. Extending inwardly still farther into the wall from the inner end of the hole 28, is a hole 29 of larger diameter still which can be formed by new blades which have been worn but little, such as represented in Fig. 14. After this series of holes has been formed, the explosive charge is packed with in the innermost hole 29 of largest diameter, and the outer end of the cavity plugged to retain the charge in the usual manner. By reason of the reduction in size outwardly, this operation will be comparatively easy, all trouble of the packing or tamping becoming caught before being driven home being obviated by reason of the hole becoming larger inwardly.

The advantages of my improved drill will now be readily understood, and briefly enumerated are as follows: First, it is made possible to maintain the length of the drill rods substantially constant, thus materially aiding in standardizing the work. Next, the frequent trips to and from the blacksmiths shop are eliminated, inasmuch as the miner himself can sharpen the old blades or replace them by new ones, and can carry a sufficient supply to last him for weeks. The blades are replaceable at a moments notice by simply pulling out the cotter pin which retains them. The blades are so constructed as to maintain their diamond 'points until they are no longer of service, being of one thickness on the outside edge and tapered in thickness toward the inside edge, this construction making it a comparatively easy matter to renew the bevel on the front edge to keep them sharpened. Considerable time is lost with the bits ordinarily provided the miner after being treated by the blacksmith in that the cutting edges are left comparatively heavy, involving considerable labor to put them into working condition. This difficulty is obviated by making it feasible to provide the miner with finished blades at small expense.

In operation, the drill may be introduced int'cT'a'p'i'ecedillfhole in the position shown in Fig. 1, the blades 6 being locked in their inward positions as long as the coupling member 7 is turned in an anti-clockwise direction. As soon as the inner end of the hole is reached and the blades are to be driven to their work, the shank is rotated in a clockwise direction, blades into..expandedposition. shown in Fig. 2 and locks them in such position in the manner already pointed out. Thus, should the blades come into contact with any soft substance, there is no danger of them closing up and becoming inoperative, the turning movement serving to maintain them in their cutting positions and removing all pos sibility of the blades being forced together into a position in which it would be impossible to operate the drill.

By an inspection of Fig. 1, it will be seen that the cutting edges are in a position not to touch the walls of a hole while the drill is being shoved thereinto preparatory to drilling an enlarged continuation thereof. Attention is called to the stops for limiting the forward and rearward quarter-turn movements, thus making it possible to employ a screw-threaded connection between the stud 16 and the blade holder socket without jamming the connection. Furthermore, by means of my improved construction, the blade holder bears against the coupling member across the entire cross section of the drill, the abutting fportions being provided with a continuous ange which corresponds to that extending throughout the shank of the tool. Furthermore, said flange terminates short of the forward end of the blade holder to enable the blades to be readily sharpened without removing the blades from said holder.

While I have described in the foregoing specification the specific construction of one embodiment of my invention, it will be readily understood that various modifications in details can be made without departing from the broad spirit of my invention which consists in the features set forth in the appended claims.

What I claim is:

1. In a device of the character described, the combination with a drill rod having a stud at its lower end, said stud being provided with cam surfaces, of a sleeve threaded to said stud, said sleeve being slotted, and blades pivotally mounted within the slots in said sleeve and in operative engagement with said cam surfaces.

2. In a device of the character described, the combination of a drill rod, with a. sleeve oscillatably mounted on the lower end of said drill rod, said sleeve being provided with oppositely disposed slots, a pivot mounted in said sleeve transversely to said slots, and blades movable within said slots about said pivot, said drill rod being provided with cam surfaces formed on its end for moving said blades.

3. In a device of the character described, the combination with a sleeve with oppositely disposed slots, of a pivot mounted the-rein transverselv to said slots, blades oscillatable on said pivot within said slots, and a stud projecting through said sleeve, said stud being rovided with recesses adapted to receive t e inside corners of said.

cutters, respectively, in contracted position, with facets for seating the ends of said blades in expanded position, and with cam surfaces connecting the bottoms of said recesses with said facets.

4:. In a device of the character described, the combination with a sleeve with oppositely disposed slots, of a ivot mounted therein transversely to sai slots, blades oscillatable on said pivot within said slots, and a stud projecting through said sleeve,

said stud being provided with recesses faces for engaging the ends of said blades adapted to receive the inside corners of said on opposite sides of said pivot from the incutters, respectively, in contracted position, side corners of the respective blades.

with facets for seating the ends of said SAMUEL T. SKEEN. blades in expanded position, and With cam In the presence ofsurfaces connecting the bottoms of said re- H. G. FLETCHER,

cesses With said facets, and other cam sur- G. M. WYATT. 

